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Cherel Yves, Hobson Keith A, Guinet Christophe, . (2015). Milk isotopic values demonstrate that nursing fur seal pups are a full trophic level higher than their mothers
. Rapid Commun. Mass Spectrom., 29(16), 1485–1490.
Keywords: Animals, Animals, Suckling, Animals, Suckling: physiology, Carbon Isotopes, Carbon Isotopes: analysis, Female, Fur Seals, Fur Seals: physiology, Lactation, Male, Milk, Milk: chemistry, Nitrogen Isotopes, Nitrogen Isotopes: analysis, Nutritional Status,
Programme: 109
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. (2015). Determinants of individual foraging specialization in large marine vertebrates, the Antarctic and subantarctic fur seals.
. The Journal of animal ecology, 84(4), 1081–91.
Abstract: The degree of individual specialization in resource use differs widely among wild populations where individuals range from fully generalized to highly specialized. This interindividual variation has profound implications in many ecological and evolutionary processes. A recent review proposed four main ecological causes of individual specialization: interspecific and intraspecific competition, ecological opportunity and predation. Using the isotopic signature of subsampled whiskers, we investigated to what degree three of these factors (interspecific and intraspecific competition and ecological opportunity) affect the population niche width and the level of individual foraging specialization in two fur seal species, the Antarctic and subantarctic fur seals (Arctocephalus gazella and Arctocephalus tropicalis), over several years. Population niche width was greater when the two seal species bred in allopatry (low interspecific competition) than in sympatry or when seals bred in high-density stabilized colonies (high intraspecific competition). In agreement with the niche variation hypothesis (NVH), higher population niche width was associated with higher interindividual niche variation. However, in contrast to the NVH, all Antarctic females increased their niche width during the interbreeding period when they had potential access to a wider diversity of foraging grounds and associated prey (high ecological opportunities), suggesting they all dispersed to a similar productive area. The degree of individual specialization varied among populations and within the annual cycle. Highest levels of interindividual variation were found in a context of lower interspecific or higher intraspecific competition. Contrasted results were found concerning the effect of ecological opportunity. Depending on seal species, females exhibited either a greater or lower degree of individual specialization during the interbreeding period, reflecting species-specific biological constraints during that period. These results suggest a significant impact of ecological interactions on the population niche width and degree of individual specialization. Such variation at the individual level may be an important factor in the species plasticity with significant consequences on how it may respond to environmental variability.
Programme: 109
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Guerreiro M, Phillips RA, Cherel Y, Ceia FR, Alvito P, Rosa R, Xavier JC, . (2015). Habitat and trophic ecology of Southern Ocean cephalopods from stable isotope analyses
. Mar. Ecol. Prog. Ser., 530, 119–134.
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Torres Leigh G, Sutton Philip J H, Thompson David R, Delord Karine, Weimerskirch Henri, Sagar Paul M, Sommer Erica, Dilley Ben J, Ryan Peter G, Phillips Richard A, . (2015). Poor transferability of species distribution models for a pelagic predator, the grey petrel, indicates contrasting habitat preferences across ocean basins.
. PloS one, 10(3), e0120014.
Keywords: Animals, Birds, Birds: physiology, Ecosystem, Models, Biological, Oceans and Seas, Predatory Behavior, Predatory Behavior: physiology,
Programme: 109
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Tartu S, Angelier F, Wingfield J C, Bustamante P, Labadie P, Budzinski H, Weimerskirch H, Bustnes J O, Chastel O, . (2015). Corticosterone, prolactin and egg neglect behavior in relation to mercury and legacy POPs in a long-lived Antarctic bird.
. The Science of the total environment, 505, 180–8.
Abstract: Seabirds often have high loads of contaminants. These contaminants have endocrine disrupting properties but their relationships with some endocrine mechanisms are still poorly investigated in free-living organisms. This is the case for the stress response which shifts energy investment away from reproduction and redirects it towards survival. In birds, this stress response is achieved through a release of corticosterone and is also accompanied by a decrease in circulating prolactin, an anterior pituitary hormone widely involved in regulating parental cares. We measured blood concentrations of some legacy persistent organic pollutants (POPs) and mercury (Hg) and examined their relationships with the corticosterone and prolactin responses of known-age (9-46 years old) incubating snow petrels (Pagodroma nivea) to a standardized capture/handling stress protocol. In this Antarctic seabird, we also investigated whether high contaminant burden correlates with a higher occurrence of egg neglect, a frequently observed behavior in snow petrels. POPs and Hg were unrelated to age. Stress-induced corticosterone concentrations were positively related to POPs in both sexes, and stress-induced prolactin concentrations were negatively related to Hg in males. Egg-neglect behavior was not related to POPs burden, but males with higher Hg concentrations were more likely to neglect their egg. This suggests that in birds, relationships between age and contaminants are complex and that even low to moderate concentrations of POPs and Hg are significantly related to hormonal secretion. In this Antarctic species, exposure to legacy POPs and Hg could make individuals more susceptible to environmental stressors such as ongoing disturbances in Polar Regions.
Keywords: Animals, Behavior, Animal, Behavior, Animal: drug effects, Birds, Birds: physiology, Corticosterone, Corticosterone: blood, Environmental Monitoring, Environmental Pollutants, Environmental Pollutants: blood, Environmental Pollutants: toxicity, Female, Male, Mercury, Mercury: blood, Mercury: toxicity, Prolactin, Prolactin: blood, Stress, Physiological,
Programme: 109
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Weimerskirch Henri, Delord Karine, Guitteaud Audrey, Phillips Richard A, Pinet Patrick, . (2015). Extreme variation in migration strategies between and within wandering albatross populations during their sabbatical year, and their fitness consequences.
. Scientific reports, 5, 8853.
Abstract: Migratory behavior, routes and zones used during the non-breeding season are assumed to have been selected to maximize fitness, and can lead to genetic differentiation. Yet, here we show that migration strategies differ markedly between and within two genetically similar populations of wandering albatross Diomedea exulans from the Crozet and Kerguelen archipelagos in the Indian Ocean. Wandering albatrosses usually breed biennially if successful, and during the sabbatical year, all birds from Kerguelen migrate to the Pacific Ocean, whereas most from Crozet are sedentary. Instead of taking the shortest routes, which would involve a return against headwinds, migratory birds fly with the westerly winds, requiring detours of 10,000 s km. In total, migrants circumnavigate Antarctica 2 to 3 times, covering more than 120,000 km in a single sabbatical year. Our results indicate strong links between migratory behavior and fitness; all birds from Kerguelen breed biennially, whereas a significant proportion of those from Crozet, especially females, are sedentary and breed in consecutive calendar years. To breed annually, these females temporarily change mate, but return to their original partner in the following year. This extreme variation in migratory behavior has important consequences in term of life history evolution and susceptibility to climate change and fisheries.
Programme: 109
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Quillfeldt Petra, Cherel Yves, Masello Juan F, Delord Karine, McGill Rona A R, Furness Robert W, Moodley Yoshan, Weimerskirch Henri, . (2015). Half a world apart? Overlap in nonbreeding distributions of Atlantic and Indian Ocean thin-billed prions.
. PloS one, 10(5), e0125007.
Abstract: Distant populations of animals may share their non-breeding grounds or migrate to distinct areas, and this may have important consequences for population differentiation and dynamics. Small burrow-nesting seabirds provide a suitable case study, as they are often restricted to safe breeding sites on islands, resulting in a patchy breeding distribution. For example, Thin-billed prions Pachyptila belcheri have two major breeding colonies more than 8,000 km apart, on the Falkland Islands in the south-western Atlantic and in the Kerguelen Archipelago in the Indian Ocean. We used geolocators and stable isotopes to compare at-sea movements and trophic levels of these two populations during their non-breeding season, and applied ecological niche models to compare environmental conditions in the habitat. Over three winters, birds breeding in the Atlantic showed a high consistency in their migration routes. Most individuals migrated more than 3000 km eastwards, while very few remained over the Patagonian Shelf. In contrast, all Indian Ocean birds migrated westwards, resulting in an overlapping nonbreeding area in the eastern Atlantic sector of the Southern Ocean. Geolocators and isotopic signature of feathers indicated that prions from the Falklands moulted at slightly higher latitudes than those from Kerguelen Islands. All birds fed on low trophic level prey, most probably crustaceans. The phenology differed notably between the two populations. Falkland birds returned to the Patagonian Shelf after 2-3 months, while Kerguelen birds remained in the nonbreeding area for seven months, before returning to nesting grounds highly synchronously and at high speed. Habitat models identified sea surface temperature and chlorophyll a concentration as important environmental parameters. In summary, we show that even though the two very distant populations migrate to roughly the same area to moult, they have distinct wintering strategies: They had significantly different realized niches and timing which may contribute to spatial niche partitioning.
Programme: 109
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Patrick Samantha C, Weimerskirch Henri, . (2015). Senescence rates and late adulthood reproductive success are strongly influenced by personality in a long-lived seabird.
. Proc. Biol. Sci., 282(1799), 20141649.
Abstract: Studies are increasingly demonstrating that individuals differ in their rate of ageing, and this is postulated to emerge from a trade-off between current and future reproduction. Recent theory predicts a correlation between individual personality and life-history strategy, and from this comes the prediction that personality may predict the intensity of senescence. Here we show that boldness correlates with reproductive success and foraging behaviour in wandering albatrosses, with strong sex-specific differences. Shy males show a strong decline in reproductive performance with age, and bold females have lower reproductive success in later adulthood. In both sexes, bolder birds have longer foraging trips and gain more mass per trip as they get older. However, the benefit of this behaviour appears to differ between the sexes, such that it is only matched by high reproductive success in males. Together our results suggest that personality linked foraging adaptations with age are strongly sex-specific in their fitness benefits and that the impact of boldness on senescence is linked to ecological parameters.
Keywords: Aging, Animals, Behavior, Animal, Birds, Birds: physiology, Feeding Behavior, Female, Life Cycle Stages, Longevity, Male, Reproduction,
Programme: 109
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Quillfeldt Petra, Cherel Yves, Delord Karine, Weimerkirch Henri, . (2015). Cool, cold or colder? Spatial segregation of prions and blue petrels is explained by differences in preferred sea surface temperatures.
. Biol. Lett., 11(4), 20141090.
Abstract: The Southern Ocean provides one of the largest environmental gradients on Earth that lacks geographical barriers, and small but highly mobile petrels living there may offer fine models of evolution of diversity along environmental gradients. Using geolocation devices, we investigated the winter distribution of closely related petrel species breeding sympatrically in the southern Indian Ocean, and applied ecological niche models to compare environmental conditions in the habitat used. We show that thin-billed prions (Pachyptila belcheri), Antarctic prions (Pachyptila desolata) and blue petrels (Halobaena caerulea) from the Kerguelen archipelago in the southern Indian Ocean segregate latitudinally, sea surface temperature being the most important variable separating the distribution of the species. Antarctic prions spent the winter north of the Polar Front in temperate waters, whereas blue petrels were found south of the Polar Front in Antarctic waters. Thin-billed prions preferred intermediate latitudes and temperatures. Stable isotope values of feathers reflected this near complete niche separation across an ecological gradient that spans large scales, and suggest evolutionary isolation by environment. In pelagic seabirds that exploit large areas of ocean, spatial niche partitioning may not only facilitate coexistence among ecologically similar species, but may also have driven their evolution in the absence of geographical barriers.
Programme: 109
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. (2014). Ecological tracers and at-sea observations document the foraging ecology of southern long-finned pilot whales (Globicephala melas edwardii) in Kerguelen waters
. Mar. Biol., 162(1), 207–219.
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